This invention relates to devices for testing pipes for obstructions and, more particularly, relates to devices for testing sewer pipes, known as sewer pipe proofers.
Devices for testing pipes and, in particular, sewer pipes, are usually in the form of a projectile which is passed through the pipe to determine if, and where, there is any blockage. Generally, these devices are in the form of an elongated section of conduit which is forced through a sewer pipe by sequentially adding sections, or continuous lengths of pipe, rod or hose, as the device is fed into the pipe being tested. The pipe tester usually has a plurality of rigid guides much smaller than the diameter of a pipe to keep it spaced from the side walls of the pipe being tested. A difficulty with the prior art devices is, however, its inability to accurately identify blockages, irregularities or deformities in the pipe. If a portion of the side wall of the pipe has been bent or deformed, it is difficult for these rigid guides to identify these places and/or blockages may be indicated where there actually are none.